Below are notes I took whilst reading the paper “Self-Monitoring via Digital Health in Weight Loss Interventions - A Systematic Review Among Adults with Overweight or Obesity”, by Michele L. Patel, Lindsay N. Wakayama and Gary G. Bennett.

Self-monitoring is a key component of standard treatments for obesity. Using digital tools, as opposed to paper-based monitoring, may reduce some of the obstacles faced when someone tries to do this, because:

  • They may reduce the time it takes to track one’s diet, e.g. with nutrition databases that automatically populate nutrition info, or features that suggest entries.
  • Wearable technologies allow for passive rather than active monitoring.
  • We may be able to raise engagement levels via individualised feedback and prompts.
  • Phones are very portable meaning that monitoring can be done in real time wherever you are, rather than retrospectively.
  • They may reduce numeracy and health literacy barriers.

This paper reviews 39 randomised controlled trials published between 2009 and 2019 which:

  • featured interventions designed to aid weight loss for participants with overweight or obesity.
  • involved the use of digital tracking tools.
  • had interventions that lasted at least 12 weeks and included outcomes around self-monitoring engagement and a weight loss outcome from at least 6 months after enrollment.

Its primary aim is to determine whether digital self-monitoring is associated with weight loss. Secondarily, it looks to understand the types of digital methods used for self-monitoring and their engagement rates in the associated interventions.

Of the 67 interventions involved:

  • 72% of them involved self-monitoring of weight.
  • 81% involved self-monitoring of dietary intake. Mostly this involved tracking food intake or calories.
  • 82% involved self-monitoring of physical activity. Mostly this meant tracking the durations of physical activity, but sometimes it was step count, types of exercises or other related items.
  • 7% self-monitored specific behaviour change goals.
  • 54% included monitoring all of weight, dietary intake and activity.

Most commonly this was done via a website (66% of treatment arms), with a lower number using mobile apps (33%), wearable devices (16%), electronic scales (12%) and text messaging (12%), PDAs (3%) or IVR technology (3%). In several cases participants were given a choice as to which method they preferred.

Some interventions used commercial websites or apps, others used websites specific to the study.

Only 9% of interventions that recommended daily digital self-monitoring engagement saw participants engage for at least 75% of the days concerned. 58% of arms saw engagements for at least half of the recommended days.

  • These numbers are higher in shorter interventions and vice versa.
  • Engagement was highest when the intervention involved self-monitoring weight. The rate was somewhat lower for diet monitoring, and lower yet for physical activity. This may be confounded by differences in the frequency prescribed the opportunities to to record.
  • Engagement was typically higher with digital as opposed to paper-based monitoring.
  • The addition of counselling usually didn’t increase the engagement rate.
  • Passive self-monitoring behaviours (e.g. wearable devices) had higher engagement rates than active self-monitoring methods, although one study showed that passive weight tracking was less associated with weight loss, perhaps because it doesn’t promote awareness of one’s behaviour as much.

Some studies compared engagement outcomes between monitoring modalities. Factors that were associated with engagement when comparison were possible include the use of:

  • incentives.
  • enhancements.
  • a wearable device.

There was a positive association between high levels of digital self-monitoring and increased weight loss in 74% of cases.

  • The rates didn’t differ much based on what was monitored, with the exception that of the 3 studies that involved monitoring behaviour change goals only 1 showed an association with weight loss.
  • Interventions that lasted at least 12 months were less likely to show an association than those that were shorter. This may either be because of rates self-monitoring engagement or weight loss declining over time.

One limitation of these studies is that participants were never randomised to different levels of self-monitoring; thus high frequency monitors are self-selected and may differ from each other in other ways.

Researchers should use strategies such as the multiphase optimisation strategy to understand the different impact of different self-monitoring strategies.

Research into how to prevent the decline in self-monitoring engagement over time is needed, as well as understanding the predictors and moderators of self-monitoring engagements. Personalisation may be needed; some people may succeed more on one self-monitoring approach than others.

In the mean time adults with overweight or obesity should be encouraged to self-monitor frequently when undergoing interventions that are aimed at weight loss.